Bobbin control for sewing machines



June 18, 1957 B. BRYSON 2,796,035

BOBBIN CONTROL FOR SEWING MACHINES Filed Dec. 20. 1954 INVENTOR 5 0 V2) BPms'o/v n BY g 2 ATTORNEY United States Patent BOBBIN CONTROL FOR SEWING MACHINES Boyd Bryson, Clifton, N. 3., assignor to Bryson Manufacturing Co., Inc., Clifton, N. 3., a corporation of New Jersey Application December 20, 1954, Serial No. 476,413

2 Claims. (Cl. 112-219) This invention relates to a device for controlling sewing machines, wherein a needle in the machine feeds a thread for cooperation with a thread fed by a bobbin to form stitches in the material passed through the machine. The invention provides a control for said machines such that when the bobbin thread breaks, or is exhausted, the electrical drive means for the sewingmachine will be automatically controlled by that condition. The invention is adapted, for example, to enable a single operator to control the automatic operation of a large number of such machines. The device of this invention may be uti- 'lized to disconnect the clutch or other driving means for the bobbin, or for such machines.

These and other advantageous objects, which will appear from the drawings and from the description hereinafter, are accomplished by the structure of my invention, of which an embodiment is illustrated in the drawings. It will be apparent, from a consideration of said drawings and the following description, that the invention may be embodied in other forms suggested thereby, and such other forms as come within the scope of the appended claims are to be considered within the scope and purview of the instant invention.

In the drawings:

Fig. l is a fragmentary side elevational view of sewing machine parts with which the bobbin control device of this invention is shown disposed in position for use,

Fig. 2 is a fragmentary plan view showing certain parts of a sewing machine and of the bobbin control device of this invention, hereinafter more particularly described,

Fig. 3 is a fragmentary side elevational view of one form of bobbin control embodying the invention, in position for control of the electric drive means for said machine responsive to a break in the bobbin thread 13,

Fig. 4 is a fragmentary elevational view of another form of bobbin control device embodying the invention, and

Fig. 5 is a perspective fragmentary view of a further form thereof.

As shown in the drawings, the device of this invention is adapted to be used in connection with a sewing machine head and table 11, bobbin 12 disposed beneath the upper face 18 of the table for feeding a bobbin thread 13, and a needle bar 14 reciprocably disposed in'the head 10, the needle 15 being secured thereto by any suitable or convenient meansfor example, by the set screw or the like. The needle thread 21 passes through the eye 22 of the needle 15, which is reciprocated, as indicated by the arrow 19, responsive to the electric drive means for the machine (not shown) which also drives the bobbin 12, and the feed dog 23. The latter moves in the well-known manner to advance the material 24 through the machine in the direction indicated by the arrow D intermediate the needle 15 and bobbin 12 for formation of the stitches 16 in said material, as shown in the stitched section 17. The bobbin control 25 of this invention comprises an elongated rod 26 having one 2,796,035 Patented June 18, 1957 ice end pivotally journalled, as at 27, in the machine or in a housing 28 for the bobbin control 25, the housing, in turn, being secured to the machine by any suitable means indicated generally by the reference character 29 in Fig. l. The point 27 at which the rod 26 is journalled in the machine is close to the plane of the lower extremity of movement of the needle and relative to the bobbin. Means are provided for normally disposing the other end 30 of the rod on a plane adjacent the plane of vertical reciprocation of the needle. The bobbin control comprises a first latch element 35 keyed to the rod 26 and a second latch element 36 disposed adjacent the first latch element. Said latch elements have complementary portions latching them together as shown in Fig. I. Said second latch element is urged to latched position by means 37 such as, a spring secured at opposite ends to the second element 36 and to the sewing machine or housing 28 for the bobbin control. The bobbin control electrical switch means, as for example indicated by the reference characters 40 in Fig. 3, 40a in Fig. 4, and 40b in Fig. 5, are provided with latch elements to control the circuit of said electrical drive means, whereby on engagement of the latching elements in their said one latching position (Figs. 1 and 4) the switch means will be disposed at the inoperative position, and on disengagement of said latching elements by tilting of the free end 30 of the rod on continued movement of the material without engagement of the bobbin thread with the needle thread, said switch means will be closed or disposed at their operative position (Fig. 3

The switch means will be disposed. at the inoperative position while the rod 26 is disposed in the plane shown in Fig. 1, while the latch elements are engaged, namely, during such time as the bobbin and the needle threads are brought together and stitched. Presser foot 31 is provided with a needle hole 32 for which a narrow slot 33 extends in the direction of travelv of the goods. The switch means of this invention may be utilized to control the clutch or other electrical circuit of the sewing machinefor example, by providing a solenoid in said circuit which Will render the clutch inoperative when the switch is closed. Pursuant to the present invention, the switch will automatically be closed upon a break in the bobbin thread 13 or upon depletion of the supply of bobbin thread as follows:

The free end 30 of the rod 26 is normally disposed just past the plane of movement of the needle thread 21 (as shown for example in Fig. 1) in the normal operation of the device and normal functioning of the machine, that is, While the bobbin thread is supplied unbroken from the bobbin for engagement with the needle thread to form the stitches 16. Upon the breaking of the bobbin thread or depletion of the supply thereof, the needle thread 21 will be carried along by the material 24 moved in the direction D by the presser foot 23, whereupon the thread 21 will be drawn at an angle as shown in Fig. 3 (instead of vertically as in Fig. l) and will tilt the rod 26, thereby tilting the latching elements out of their latched (Fig. 1) position into their disengaged, unlatched position shown in Fig. 3.

Said latching elements may comprise a nosing point 45 on one of the elements engaging a complementary face 46 on the other element for said interlatching engagement, or any other interlatching complementary elements suitable to the same end. The device may be provided with resetting means, as for example, shown at 47 in Fig. 2, keyed to latching element 36. The switch means (40, 40a, 40b) may comprise suitable complementary contact members secured to the latch elements 35, 36 and so disposed thereon that when such latch elements 35, 36 are in their latching position, the contact members will be out of contact with each other and said switch means will be 3 sodisposed at their open-or inoperative position, while, when such latch elements are disengaged, the switch contact members will be in contact with each other and said switch means will be disposed in their closed or operative position.

The latch element 36 may be pivotally mounted as at 48 in the machine. The switch means may comprise a switch member secured to one of the latch elements and rendered open while said latching elements are in one position (Fig. 1) and closed while said latching elements are in their otherposition (such as Fig. 3). This end may be attained by providing a switch element 40 for example, which will be operative to its openand closed positions on tilting of one latch elementas,-for example, by forming switch element 40 as a mercury switch for closing the lead Wires 49, 50 for controlling the circuit, said switch being operative when the latch elements are disengaged, as in the Fig. 3 position. Or the electric switch means may comprise complementary contact members, as in the case of the electric switch 40a shown in Fig. 4 comprising the electric contact members 41 and 42. One of said elements may, for example, be fixed to the switch casing and the other element 42 may be carried by a latch element so that when the latch elements are in their engaged position (Fig. 4), said contacts will be held apart, and, when the latch elements are disengaged, as in the Fig. 3 position, the contact members will be brought together to close the switch. In the form shown in Fig. 5 one switch element 43 may be fixed to the switch housing or other stationary part and the other switch element 44 fixed to one of the latch parts, such as 36, and moved in the direction of the arrow 39 on rotation of the latch elements to their inoperative position, thereupon closing on the element 43 to close the switch.

The action of the switch elements may be reversed, that is they may be rendered closed when the latch elements are in latching engagement and open on disengagement of the latch elements depending on the electrical means to be controlled.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A bobbin control for a machine for sewing stitches into material, said machine having a bobbin and electrical means for energizing said machine, and having a feed dog and a needle journalled in the machine for vertical reciprocation therein relative to the feed dog, with thread passing through the needle end for cooperation with thread from said bobbin to form stitches in the material, said bobbin control comprising an elongated mounted on the machine, the free end of'the rod adapted to be positioned adjacent the point of vertical reciprocation of the needle, disposing the rod parallel to the feed dog, a first latch element secured to said red at substantially the pivot point for the rod for pivotal movement of the first latch element with the rod on a short radius on said pivot point, a second latch element pivotally mounted in the support intermediate the pivot point for the rod and the free end of the rod, a nosing on one of said latching elements and a complementary face on the other latch element so that said latch elements will'be in engagement when the rod is disposed in parallel relation to the feed dog and the second element is moved in one direction, means engaging the second latch element and support intermediate the pivot point for the rod and the free end of the rod, urging said second element in said one direction for engagement with the first latch element when the rod is disposed in a plane parallel to the feed dog and to rotate said second element past its position of engagement when the rod is tilted out of its position of parallel relation to the feed dog on continued movement of the material without engagement of the bobbin thread, and complementary electrical switch means on one of said latch elements to close the circuit of said electrical means for energizing the machine when disposed in one switch position, and to open said circuit when disposed in the other switch position, such that, on engagement of said latching elements in their said one latching position, said switch means will be disposed in one switch position, and, on the continued movement of the material without engagement of the bobbin thread with the needle thread, said needle thread will bear against the other end of the rod and rotate the rod, disengaging said latching elements, said switch means will be disposed at their other switching position, to thus selectively control said electrical energizing means through the bobbin control.

2. In a bobbin control for a machine for sewing stitches into material as set forth in claim 1, said means urging the second element being spring means.

References Cited in the file of this patent UNITED STATES PATENTS 2,387,958 Vossen Oct. 30, 1945 2,643,305 Mansson June 23, 1953 2,747,039 Vossen May 22, 1956 

